Measuring catalyst(s) for filling reactor tubes in reactor vessels

ABSTRACT

A plurality of reactor tubes contained in a reactor vessel are filled with at least one catalyst by automatically measuring the catalyst by weight with equipment located at the site of the reactor vessel, and dispensing the measured catalyst into a plurality of reactor tubes.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a division application of U.S. application Ser. No.10/609,081, filed Jun. 27, 2003, which claims the benefit of U.S.provisional application No. 60/392,750 filed Jun. 28, 2002.

STATEMENTS REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

Not applicable.

REFERENCE TO A MICROFICHE APPENDIX

Not applicable.

BACKGROUND OF THE INVENTION Description of the Related Art

Refer to the “Background of the Invention” section and other sections ofU.S. Pat. No. 5,897,282, which is incorporated herein by reference, forgeneral information concerning techniques and apparatus used to fillreactor tubes in catalyst reactor vessels with catalyst material(s).

Various techniques have been used in the past to load catalyst intoreactor tubes. One method filled tubes by volume. However, reactor tubesfilled with equal volumes of catalyst may have a five percent to tenpercent variance in weight (e.g. a thirty to forty gram variance)between the actual catalyst contained in respective tubes. Another priormethod pre-measured catalyst by weight and individually sealed eachmeasured amount into a resealable plastic bag at an off-reactor-sitelocation. The plastic bags were then transported by drum to the worksitefor loading into multi-compartment tube loaders or into reactor tubes.Once at the worksite, the drums were opened and bags removed forloading, e.g. ten bags at a time into tube loaders. This technique isvery laborious as it may call for the pre-bagging of 100's of thousandsof bags prior to arriving at the worksite followed by unbagging at theworksite. In another technique, individual quantities of catalyst wereweighed by hand and then collected by hand for loading into a reactortube. Last, in another technique which was learned about throughsecondhand conversations, it is believed BASF used a hopper to feedcatalyst to a scaling belt conveyor, which led to a single tube, whichwas used to feed catalyst directly into a reactor tube. This device onlyfilled one reactor tube at a time, and it was described as being slow.

BRIEF SUMMARY OF THE INVENTION

A plurality of reactor tubes contained in a reactor vessel are filledwith at least one catalyst by automatically measuring the catalyst byweight with equipment located at the site of the reactor vessel, anddispensing the measured catalyst into a plurality of reactor tubes. Thesystem improves efficiency, and saves time and wasted catalyst.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

FIG. 1 is a schematic view of a reactor vessel worksite.

FIG. 2 is an elevation view of a device for feeding and weighingcatalyst.

FIG. 3 is a top view of a five lane device for feeding and weighingcatalyst.

DETAILED DESCRIPTION OF THE INVENTION

Referring to FIG. 1, a reactor vessel worksite 10 is schematicallyshown. The reactor vessel 12 contains a plurality of reactor tubes 14.The reactor tubes 14 extend vertically in the axial direction. One endof each reactor tube 14 is connected to a lower tube sheet 16 and theother end is connected to an upper tube sheet 18. The reactor vessel 12has an opening, entryway or removable head 20 to expose the upper tubesheet 18. From the upper tube sheet 18, each reactor tube 14 is designedto be filled with catalyst material(s) 22 for the purpose of carryingout the reaction.

A bulk catalyst material(s) 24 which may or may not be pre-mixed isdelivered to the worksite location 10 for the reactor vessel 12. Thebulk catalyst material(s) 24 may be delivered, for example, in a drum26. Next, the material(s) is/are transferred to an automated device forfeeding and measuring the bulk catalyst material(s) 30 which may bemounted on a platform 21. The automated device 30 can be made to fillmultiple reactor tubes 14 at the same time or one reactor tube 14 at atime. The bulk catalyst material(s) 24 is/are measured by weight. Aftera desirable weight has been measured, the resulting quantity of themeasured catalyst 28 is separately dispensed. Additional desirableweight quantities of the catalyst may be measured and separatelydispensed. Weight measurements for each quantity may be performedsimultaneously, sequentially, or part simultaneously and partsequentially. Each separate measured quantity of the catalyst 28 isdispensed into an individual reactor tube 14.

The process described in the preceding paragraph can be repeated foradditional or different bulk catalyst material(s) 24 to be placed on topof the initial quantity of catalyst which has been loaded into a reactortube 14.

Referring to FIG. 2, one embodiment of the automated(self-acting/operating/regulated/controlled) device for feeding andmeasuring the bulk catalyst material(s) 30 is shown. This embodimentgenerally includes a feed hopper 32 (optional), a feed trough 34(optional), a main hopper 36, a vibrating trough 40, a vibrating motor50, a gate mechanism 60, a catalyst dispenser 70, a scale 80 and acomputer 90.

A drum 26 or other device is used to transfer bulk catalyst material(s)24 a to the automated device for feeding and measuring the bulk catalystmaterial(s) 30. The drum 26 may be mounted above the feed hopper 32, thefeed trough 34, or the main hopper 36. If the feed hopper 32 isincorporated into the system, it will feed catalyst materials onto thefeed trough 34. The feed trough 34 (such troughs are commerciallyavailable with a screening device in the trough), if incorporated, isused to screen broken pieces, dust, etc. and is used to feed (byvibration, gravity, etc.) catalyst materials to the main hopper 36. Themain hopper 36 is mounted above and feeds catalyst material(s) onto thevibrating trough 40 in a uniform manner (such hoppers 36 with uniformfeed outlets are commercially available). The feeding of the catalystmaterial(s) onto the vibrating trough 40 in a uniform manner keepsunwanted weight off of the vibrating trough 40, i.e., it prevents thebuild-up of a load within vibrating trough 40 of catalyst havingexcessive weight.

The vibrating trough 40 may have a flat base 42 with two sidewalls 44(one shown). One or more vibrating motors 50 (preferably variable speed)are connected to the lower side of the vibrating trough 40. As acatalyst material 24 is fed onto the flat base 42, the vibrating motor50 shakes the vibrating trough 40. This functions to feed/move thecatalyst material (or materials) 24 b along the vibrating trough 40 anddivaricates the catalyst material on the flat base 42 as it moves alongthe trough. The vibrating trough 40 may have a slight decline inaltitude from the entering end 45 to the exiting end 46. The vibratingtrough 40 may be replaced by some other device for moving the catalyst,such as, for example, a belt conveyor or other type of conveyor. Thevibrating motor 50 includes control lines 52 which run to the computer90. The computer 90 determines when and how much to vibrate thevibrating trough 40 via the vibrating motor 50.

A gate mechanism 60 is mounted over the exiting end 46 of the vibratingtrough 40. The gate mechanism 60 includes a brush 62 or other devicesuch as, for example, a catch or flapper (not shown). The gate mechanism60 also includes control lines 64 which run to the computer 90 and to apower source. The computer 90 determines when the brush 62 is lifted(open) and when it is lowered (closed). When lifted, catalyst material24 b may be moved/vibrated off of the exiting end 46 of the vibratingtrough 40.

A catalyst dispenser 70 is mounted below the exiting end 46 of thevibrating trough 40. The catalyst dispenser 70 collects catalystmaterial 24 b moved/vibrated off of the exiting end 46 of the vibratingtrough 40. Moreover, the catalyst dispenser 70 is used to weigh thecatalyst material 24 b which is collected. This may be accomplished by ascale 80 or load cell device connected to the catalyst dispenser 70.Control lines 82 run from the scale 80 to the computer 90. The computer90 determines/measures the weight of the catalyst collected in thecatalyst dispenser 70 and integrates this data with data for operatingthe vibrating motor 50 and for opening or closing the gate mechanism 60.More than one quantity of catalyst can be weighed at the same time usingmultiple catalyst dispensers 70 each paired with a scale 80.

The catalyst dispenser 70 may be a dump bucket 72 which may or may notpivot. The catalyst dispenser 70 could also include, for example, a doormechanism 74, etc. for dispensing the measured catalyst. Control lines76 may be used to automate the door mechanism 74 via a pivot point 78.

The catalyst dispenser 70 is used for dispensing a measured quantity ofcatalyst 22 into a reactor tube 14. This may be accomplished in avariety of ways, such as, for example, by dispensing each measuredquantity of catalyst (one or more quantities of catalyst can be measuredat the same time) into a funnel (or funnels) 84 which feeds suchmeasured quantity into a transfer cassette (or cassettes) 86 having aplurality of catalyst loading compartments 88 (e.g. five or tencompartments) and used to hold catalyst by weight (similar to a transfercassette commercially available from Bulk Material Equipment of Houston,Tex. which is used to hold catalyst by volume), by dispensing eachmeasured quantity of catalyst into a storage bag, by dispensing eachmeasured quantity of catalyst into a device (not shown) for transferringcatalyst directly into reactor tubes 14, etc. The transfer cassette(s)86 are currently preferred and are then taken to, for example,multi-tube loaders (not shown) which load catalyst into a reactor, afunnel, etc.

The computer 90 preferably includes a user interface such as a keypad 92and display screen 94. The keypad 92 may be used to enter operationalparameters such as the target weight for each measured quantity ofcatalyst 24 b, the measurement rate or time allotted to measure eachsuccessive quantity of measured catalyst (e.g. ten to twentymeasurements/compartments per minute), and/or allowable/desirablevariance between each successive quantity of measured catalyst to bedispensed into a reactor tube 14. Presently, it is recommended to haveless than a three gram variation (preferably less than a one gramvariation) between each measured quantity of like catalyst to be loadedinto respective reactor tubes 14 (although the allowable variation maydepend upon the job being performed as would be known to one of ordinaryskill in the art, e.g., the weight and size of the individual catalystparticles depends upon the job being performed and would affect theallowable variation between each measured quantity). The display screen94 may display by way of example, the production weight target, theactual weight of each successive measured quantity, the running speed,an average of weights, and/or the allowable variance between the targetweight and each successive measured weight. Generally, the computer 90may slow down the vibrating motor 50 and hence the rate of catalyst 24 bfalling into the catalyst dispenser 70 as the actual weight approachesthe target weight. This slow down process may be dependent upon theallowable variance in weight. The accuracy of the measurements may alsoincrease with each successive production of a measured quantity as thecomputer 90 can calibrate the system based upon prior readings of, forexample, the actual weight versus the target weight while incorporatingprior data on the vibration rate and amplitude, gate open time,accounting for drop distance and particles falling through the air afterthe signal is sent to close the gate, etc.

Referring to FIG. 3, a five lane embodiment of the automated(self-acting/operating/regulated/controlled)device for feeding andmeasuring the bulk catalyst material(s) 30 a is shown. The automateddevice for feeding and measuring the bulk catalyst material(s) 30 a isnormally set-up at the reactor vessel worksite 10 (depicted in FIG. 1).This embodiment generally includes a hopper trough 35, five main hoppers36 a-e, five vibrating troughs 40 a-e, five vibrating motors (hidden butsimilar to as shown in FIG. 2), five gate mechanisms 60 a-e, fivecatalyst dispensers 70 a-e, five scales 80 a-e and a computer 90. Thisembodiment may be used to measure and fill twenty to forty compartments88 (FIG. 2) per minute, however such is somewhat dependent upon the sizeand weight characteristics of the catalyst being used. By way ofexample, this embodiment could be used to load a transfer cassette 86having ten catalyst loading compartments 88 in series by loading everyother compartment on a fist run, next shifting/sliding the transfercassette 86 to align the five remaining empty compartments 88 under thedevice 30 a, and then loading the five remaining compartments 88.

Catalyst 24 a is fed to each of the main hoppers 36 a-e by the hoppertrough 35. and passes down through openings 37 onto the five lanes ofvibrating troughs 40 a-e. The vibrating troughs may each be mounted onindependent scales 80 a-e. Catalyst dispensers 70 a-e are mounted belowthe exit and gate mechanisms 60 a-e of the respective vibrating troughs40 a-e. The catalyst dispensers 70 a-e collect catalyst material 24 bmoved/vibrated off of the respective vibrating troughs 40 a-e. Moreover,the catalyst dispensers 70 a-e are used to weigh the catalyst material24 b which is collected. This may be accomplished by respective scales80 a-e or load cell devices connected to the catalyst dispensers 70 a-e.Control lines 82 similar to as shown in FIG. 2 run from each of thescales 80 a-e to the computer 90. The computer 90 determines/measuresthe weight of the catalyst collected in each of the catalyst dispensers70 a-e (preferably independently) and integrates this data with data foroperating the five separate vibrating motors 50 (similar to as shown inFIG. 2) and for opening or closing the gate mechanisms 60 a-e. Asdiscussed above with respect to FIG. 2, each of the gate mechanisms 60a-e preferably has a brush tip 62 to enhance the closing of the gatemechanisms 60 a-e against falling particles of the catalyst material 24b. Preferably the computer 90 determines/measures the weight of thecatalyst collected in each of the catalyst dispensers 70 a-eindependently and closes each respective gate mechanism 60 a-eindependently in response to the separate computations.

Some data resulting from test runs of the automated devices for feedingand measuring the bulk catalyst material(s) 24 a is reproduced below asan example of successive measurements by weight of catalyst which areachieved by the equipments:

TARGET WT. 908 GRAMS TARGET WT. 453 GRAMS (BRUSH) (METAL FLAPPER) 14.515 PER MINUTE & 5 PER SECOND PER MINUTE 4 PER SECOND 1 452.5 1 906.5 2452 2 907.5 3 463 3 909.5 4 462 4 906.5 5 452 5 906 6 452.5 6 907 7 4527 906.5 8 453.5 8 908 9 451 9 906.5 10 453.5 10 905 11 456.5 11 911 12459.5 12 910.5 13 453.5 13 905.5 14 453 14 906.5 15 453.5 15 909 16453.5 16 905.5 17 453.5 17 909 18 454.5 18 907 19 454.5 19 907 20 455.520 908 21 456 21 905 22 454 22 905 23 454 23 905.5 24 455.5 24 905.5 25454.5 25 909 26 454 27 455 Total weight 12274.5 22678 Average weight454.6 907.12 Low weight 452.5 905 High weight 463 911

Various changes may be made to the embodiment described withoutdeparting from the spirit of the invention claimed. For example,multiple automated devices for feeding and measuring the bulk catalystmaterial(s) 30 may be combined to form, for example, two simultaneousfive lane loaders to make a ten lane loader; or a plurality of vibratingtroughs 40 may be interconnected to form a multi-channel vibratingtrough 40. It is to be understood, however, that the loader is notlimited to two, five or ten lanes (it could be more or less lanes). Thetransfer cassette 86 may also be automated to move with respect to thecatalyst dispenser 70. In this manner, a single scale 80 and catalystdispenser 70 may perform automated filling of all compartments 88 in atransfer cassette 86. The automated device for feeding and measuring thebulk catalyst material(s) 30 allows such to be accomplished quickly,i.e., at speeds greater than one compartment 88 (and hence one reactortube 14) per minute, and up to speeds of ten to twenty compartments 88(and hence reactor tubes 14) per minute or greater. This is asignificant advantage over the prior art and is critical to makingmeasurement by weight an improvement over the prior art. The system mayalso incorporate photo eyes for viewing catalyst to adjust the feed, andcan control the feed rate of the hoppers 32, 36. The system has theadvantages over prior systems of being cleaner, more accurate in termsof dispensing the proper and uniform amounts of catalyst 22 into thereactor tubes 14, operationally faster, and decreasing spillage.

1. A method for filling a plurality of reactor tubes contained in a reactor vessel with at least one catalyst, comprising: feeding the catalyst into a plurality of main hoppers: passing the catalyst from the plurality of main hoppers onto a plurality of independent lanes; vibrating the catalyst across the plurality of independent lanes until the catalyst traveling across each of the plurality of independent lanes reaches a plurality of respective gating mechanisms: collecting the catalyst moving off of each of the plurality of independent lanes, and automatically and independently measuring a plurality of respective quantities of the catalyst by weight; independently closing the plurality of respective gating mechanisms as determined by said step of automatically and independently measuring a plurality of respective quantities of the catalyst by weight; and dispensing the plurality of quantities of the measured catalyst into a plurality of respective reactor tubes.
 2. The method according to claim 1 further including: delivering a bulk catalyst to a location of the reactor vessel for the purpose of measuring the catalyst performed prior to said feeding step.
 3. The method according to claim 1 further including dispensing a plurality of the quantities of the measured catalyst into a multi-compartment cassette prior to said step of dispensing the plurality of quantities of the measured catalyst into a plurality of respective reactor tubes.
 4. The method according to claim 1 wherein said step of independently closing the plurality of respective gating mechanisms comprises closing by lowering a brushing mechanism over an end of each of the plurality of independent lanes. 